Cash Flow Information - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Other Significant Noncash Transactions [Line Items]
Cash paid for interest	$ 28,900	$ 27,200
Net of capitalized interest	2,900	3,100
Line of credit facilities gross borrowings	0	202,000
Line of credit facilities gross repayments	53,000	297,000
Lease Termination Revenue Non Cash	$ 4,200	$ 0
Noncash Investing and Financing Activities Related Text	Paydowns of the 2014 5-Year Term Loan and the 2015 5-Year Term Loan of $150.0 million each were made in the six months ended June 30, 2018, which were directly paid from the 2018 Term Loan Facility borrowing and are considered to be non-cash transactions.